The subject matter disclosed herein relates generally to the field of elevators, and more particularly to a multicar, self-propelled elevator system having a cooled linear propulsion system.
Self-propelled elevator systems, also referred to as ropeless elevator systems, are useful in certain applications (e.g., high rise buildings) where the mass of the ropes for a roped system is prohibitive and there is a desire for multiple elevator cars to travel in a single lane. There exist self-propelled elevator systems in which a first lane is designated for upward traveling elevator cars and a second lane is designated for downward traveling elevator cars. At least one transfer station is provided in the hoistway to move cars horizontally between the first lane and second lane.
Existing self-propelled elevators employ linear motors having primary portions that include stator coils engaged to a support structure. Duty cycle loads between coils and/or coil modules may vary from two percent to an excess of thirty percent depending upon the car speed and location within the hoistway. Because the duty cycle varies, the coils dissipate spatially varying heat loads in the hoistway causing a variance in coil efficiency and useful life from one coil to the next. Improvements in coil cooling is desirable.